Arrangement for fixing a wiper device which can be used to retract the drive shaft in the event of an impact

ABSTRACT

An arrangement for fixing a wiper device for a motor vehicle includes at least one stand for guiding and fixing a drive shaft that extends axially in a substantially vertical direction. The stand includes a barrel in which the shaft is guided in rotation, and a horizontal base plate for fixing the stand to a structural element of the vehicle, by a damper block made of an elastically deformable material. The damper block is fixed to the structural element by a fixing element, which includes a vertical rod that passes through the damper block and is connected to the structural element, and an element for locking the damper block on the structural element. The rod and locking element are connected by connection means for enabling the rod and locking element to disconnect, through downward sliding of the locking element with respect to the rod, when subjected to a violent impact.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a national stage application based on InternationalApplication No. PCT/FR02/04186 filed Dec. 4, 2002.

FIELD OF THE INVENTION

The invention concerns an arrangement for fixing a wiping device for amotor vehicle.

BACKGROUND OF THE INVENTION

The invention concerns more particularly an arrangement for fixing awiping device for a motor vehicle, of the type comprising at least onestand for guiding in rotation and fixing a drive shaft which extendsaxially in a substantially vertical direction, of the type in which thestand comprises a barrel in which the shaft is guided in rotation, and ahorizontal base plate for fixing the stand with a body structure elementof the vehicle, by means of a damper block made from elasticallydeformable material, of the type in which the damper block is fixed tothe body structure element by a fixing element comprising a vertical rodwhich passes through the damper block and which is connected to the bodystructure element, and an element for the vertical locking of the damperblock in the fixed position on the body structure element.

Such a stand constitutes a conventional mechanism for fixing the wipingdevice to the vehicle body.

In the event of collision of the vehicle with a pedestrian, the part ofthe wiper mechanism which extends outside the vehicle constitutes ablunt object which may cause injuries.

It has also been remarked that, in the case of violent accident, thewiping device, which is arranged in the engine compartment close to thecabin, could penetrate inside the cabin through the windscreen openingunder the effect of the impact.

The accidental intrusion of an element as solid as this then proves tobe dangerous to the safety of the passengers and it has thereforeappeared necessary to better predict the behaviour of the wiper devicein the event of violent impact.

The existence of means allowing retraction of the stand, in particularin the document FR-A-2.733.474, is known, in which the stand comprises arupture initiation area, and in the document EP-A-0.916.559, in whichthe drive shaft retracts axially into the guide barrel.

However, these solutions have recourse to parts with complex shapes oradditional parts. It is then no longer possible to use standard partsand the result is an additional cost during manufacture.

SUMMARY OF THE INVENTION

The aim of the invention is to propose a stand allowing retraction ofthe drive shaft in the event of axial impact, and which uses standardparts.

To this end, the invention proposes an arrangement of the type describedpreviously, characterised in that the rod and locking element areconnected by connection means enabling the rod and locking element to bedisconnected, through a substantially vertical downward sliding of thelocking element with respect to the rod, when the wiping device issubjected to a violent impact whose vertical component is orienteddownwards and is greater than a given value, thus allowing separation bya vertical downward sliding of the damper block with the body structureelement, in order to obtain axial retraction of the base plate, guidebarrel and drive shaft.

According to other characteristics of the invention:

-   -   the connection means comprise at least one elastically        deformable element;    -   the connection means comprise at least one element for retaining        the locking element which is attached to the rod and which is        able to disconnect from the rod at the time of impact;    -   the connection means comprise at least two lugs able to deform        radially outwards received by the bottom end of the locking        element, and whose substantially vertical internal faces        cooperate with the wall of the rod for the connection of the        locking element with the rod;    -   the connection means comprise at least one plastically        deformable element;    -   the rod comprises, close to its bottom end, at least one lug        curved towards the outside which is in abutment against a bottom        face of the locking element;    -   the locking element comprises a tubular and/or cylindrical        sleeve extending substantially vertically which has the rod pass        through it, the internal wall of the tubular sleeve and the        external wall of the rod being connected by cooperation of        complementary shapes;    -   the connection means comprise at least one rupture initiation        area;    -   the locking element and the rod are two parts of the same fixing        element, and the rod is connected to the locking element by the        rupture initiation area;    -   the locking element is connected to the rod by an intermediate        element, and the locking element is connected to the        intermediate element by the rupture initiation area.

BRIEF DESCRIPTION OF THE DRAWINGS

Other characteristics and advantages of the invention will emerge from areading of the following detailed description, for an understanding ofwhich reference will be made to the accompanying drawings, in which:

FIG. 1 is a perspective view of part of the wiping device according tothe teachings of the invention;

FIG. 2 is a perspective view of a rod of the element for fixing thewiping device according to the teachings of the invention;

FIG. 3 is a view in longitudinal axial section of the wiper device ofFIG. 1 through a plane passing through the vertical axes of the shaftand damper block;

FIG. 4 is a view similar to that of FIG. 3 on which the guide stand anddrive shaft are shown retracted after an impact;

FIG. 5 depicts, in axial longitudinal section and to a larger scale, thedetailed embodiment of the damper block and fixing element according tothe invention;

FIG. 6 is a view similar to that of FIG. 5, depicting a secondembodiment of the fixing element, in accordance with the invention;

FIG. 7 is a perspective view of the locking element depicted in FIG. 6;and

FIGS. 8 to 12 are views similar to those of FIG. 6, depicting five otherembodiments of the fixing element, in accordance with the invention.

DETAILED DESCRIPTION

In the description which follows, identical, similar or analogouselements will be designated by the same reference numbers.

FIGS. 1, 2 and 3 depict a wiper device 20 for a motor vehicle window(not shown) which comprises a stand 22, and a shaft 24 for driving awiper arm (not shown).

The stand 22 allows the guidance in rotation and fixing of the shaft 24.It comprises a tubular barrel 26 of vertical axis A1 which is designedto receive, for rotation about its axis A1, the shaft 24.

By way of non-limiting example, the axis A1 is here oriented vertically.

For fixing it to a body structure element 30 of the vehicle, the stand22 comprises a base plate 32 which extends substantially horizontallyfrom the barrel 26, that is to say in a plane perpendicular to the axisA1.

The stand 22 also comprises a stub 34 which extends horizontally fromthe barrel 26 and which serves for connecting the stand 22 to the drivesystem (not shown) of the wiper device 20.

The top end 36 of the shaft 24 projects axially outward beyond the topend of the barrel 26 so as to enable the wiper to be mounted on aconical bearing surface 38, in this case notched, against which thewiper is intended to be clamped axially by a nut (not shown) screwedonto the free top end threaded portion 36 of the shaft 24.

To allow the rotational driving of the shaft 24, a crank 40 is providedwhich is mounted so as to be rotationally integral with the bottom endof the shaft 24, substantially perpendicular to the axis A1 of the shaft26.

For its connection with a control linkage (not shown), itself driven bya geared motor (not shown), the crank 40 has, at its free longitudinalend 40 opposite to its end for fixing to the shaft 24, a sphericalswivel 44 which is intended to be received in a housing of complementaryshape (not shown) carried by the linkage.

According to a generally known design, particularly in order to dampvibrations, the base plate 32 is fixed to the body structure element 30by means of a damper block 46 which is for example a block ofcylindrical shape overall made from elastomer material.

The damper block 46 extends along a vertical axis A2 substantiallyparallel to the axis A1 of the shaft 24.

It is known how to produce the block 46 in the form of an element madefrom elastomer material moulded on around a central fixing element 48.The fixing element 48 comprises a tubular rod 50 with an annularcross-section which passes axially through the damper block 46.

The tubular rod 50 comprises a top thread 52 which receives a screw 54for fixing the rod 50 to the body structure element 30. The rod 50 alsocomprises a horizontal top collar 56 whose bottom face 56 i is inabutment against a top face 46 s of the block 46 and whose top face 56 sis in abutment on a bottom face of the body structure element 30, underthe clamping action of the screw 54.

The fixing element 48 also comprises a locking element 64 which makes itpossible to fix the block 46 to the fixing element 48. The lockingelement 64 is in general a horizontal washer whose top face 64 s is inabutment against a bottom face 46 i of the block 46, and which isconnected to the rod 50 by connection means.

Thus the block 46 is fixed vertically between the collar 56 of the rod50, and the locking element 64, the axial mounting preferably beingclamped.

The block 46 is mounted in a complementary housing 68 in the base plate32. More precisely, the housing 68 is a hole with a circular contourwhose dimensions correspond to those of a groove 69 formed in thelateral cylindrical wall of the damper block 46.

In accordance with the teachings of the invention, the connection meansbetween the locking element 64 and the rod 50 enable the locking element64 and the rod 50 to be disconnected in the event of violent impact, inparticular in the event of collision with a pedestrian. Thisdisconnection thus enables the block 46 to slide vertically downwardswith respect to the rod 50. Thus the rod 46 can be disconnected from thefixing element 48, which makes it possible to obtain axial retraction ofthe base plate 32, the barrel 26 and the drive shaft 24.

However, disconnection is possible only with an impact orienteddownwards, that is to say which comprises a vertical component orienteddownwards.

According to a first embodiment of the invention depicted in FIGS. 2 to5, the bottom end of the rod 50 comprises lugs 70 which are curvedradially outwards and crimped so as to be in abutment against the bottomface 64 i of the locking element 64 (FIG. 5), thus forming theconnection means.

The lugs 70 are sized so that, in the event of a violent impact, theydeform plastically and/or break, so as to come into axial alignment withthe rod 50. Thus the lugs 70 no longer hold the locking element 64,which can then disconnect from the rod 50.

FIG. 8 depicts another embodiment of the invention according to whichthe connection means deform plastically at the time of impact.

The locking element 64 comprises a tubular sleeve 72 which extendsvertically upwards passing through the block 46, and which has the rod50 pass through it. The means of connection between the rod 50 and thelocking element 64 are shapes in relief 74 a arranged on the convexexternal face of the rod 50 which cooperate with complementary shapes 74b on the internal face of the tubular sleeve 72.

Here the complementary shapes in relief 74 a, 74 b are in the form ofsuperimposed annular cams. They can however be of any other shape, suchas a knurling of the peripheral wall of the rod 50, or a male/femalethread assembly of a nut and screw connection, one element of which ismade from more malleable material than the other.

To allow the disconnection of the locking element 64, the dimensions andmaterials making up the complementary shapes 74 a, 74 b are chosen so asto deform at the time of impact. The tubular sleeve 72, and thereforethe locking element 64, can then slide along the rod 50, until completedisconnection takes place.

FIGS. 6, 7 and 10 depict two embodiments of the invention in which theconnection means are elastically deformable.

According to the embodiment depicted in FIGS. 6 and 7, the rod 50 andthe locking element 64 are two parts of the same fixing element 48.

The locking element 64 comprises a tubular sleeve 72 which extendsvertically upwards passing through the block 46 and which has the fixingscrew 54 pass through it. The rod 50 consists of lugs 76 which extendaxially downwards from the bottom face of the locking element 64.

The internal faces 78 of the lugs 76 comprise a female thread whichcooperates with the male thread on the fixing screw 54, thus affordingthe fixing of the locking element to the fixing screw 54. Each lug 76comprises an area 80 of reduced thickness. The area of low elasticstrength 80 thus formed enables the lugs 76 to move away radiallytowards the outside under the ramp effect exerted by the complementarythreads at the time of impact, thereby allowing the disconnection of thelocking element 64 from the fixing screw 54.

According to the embodiment depicted in FIG. 10, the connection meansconsist of an element 82 attached to the rod 50.

This attached element 82 is here a split elastic ring 82 which isreceived in a complementary groove 84 in the rod 50. This ring 82 makesit possible to stop the locking element 64 in vertical sliding towardsthe bottom.

An elastic ring 82 of the circlip type has been shown. However, it maybe replaced by any elastic annular element such as for example a bracingring of the “Grifaxe” type, or by a spring ring.

The dimensions and material of the ring 82, as well as the depth of thegroove 84, are determined so that the ring 82 can emerge from the groove84 at the time of impact, thus allowing the disconnection of the lockingelement 64.

According to another variant of the invention depicted in FIGS. 9 and11, the fixing means comprise a rupture initiation area 86.

According to the embodiment depicted in FIG. 9, the rod 50 and thelocking element 64 are two parts of the same fixing element 48.

The locking element 64 comprises a tubular sleeve 72 which extendsvertically upwards passing through the block 46, and which has thefixing screw 54 pass through it. The rod 50 is here a threaded tubularelement which extends axially downwards from the bottom face 64 i of thelocking element 64.

The rod 50 is connected to the locking element 64 by the ruptureinitiation area 86, which has a cross-section sized so as to break atthe time of impact, thus allowing the disconnection of the lockingelement 64.

According to the embodiment depicted in FIG. 11, the locking element 64comprises a threaded element 88 which extends vertically upwards andwhose male thread cooperates with the female thread of the rod 50 inorder to effect the fixing of the locking element 54.

The threaded element is connected to the horizontal part of the lockingelement 64 by the rupture initiation area 86.

The cross-section of the rupture initiation area 86 is sized so as tobreak at the time of impact. Because of this, the horizontal part of thelocking element 64 and the threaded element 88 disconnect, the threadedelement remaining screwed in the rod 50, and thus allowing thedisconnection of the locking element 64.

To allow the initial screwing of the locking element 64 into the rod 50,as well as the removal of the threaded element 88 after rupture, thelocking element 64 comprises a shape 90 of the “hexagonal” type. Thisform 90 makes it possible to manoeuvre the locking element 64 and thethreaded element 88 by means of a complementary screwing key (notshown).

FIG. 12 depicts another embodiment of the invention which allows aseparation of the base plate 32 from the body structure element 30.

Before it is fixed to the body structure element 30, as depicted in finelines, the block 46 is cylindrical and tubular in shape, of verticalaxis “A2” and with an outside diameter “D” substantially equal to theinside diameter of the housing 68 in the base plate 32. The block 46also comprises a central axial hole 92 of diameter “d”, and the top endof the block comprises an external radial shoulder 94.

The fixing element 48 comprises a tubular cylindrical top part 96 ofvertical axis “A2” which passes through the hole 92 and has the fixingscrew 54 pass through it. The top part 96 of the fixing element 48 isextended axially by a bottom part 98.

The bottom part 98 is a curved element of revolution, of vertical axis“A2” and with a diameter “d1” greater than the diameter “d” of the hole92 in the block 46. The bottom part also comprises a thread 100 intendedto receive the fixing screw 54.

When the wiping device 20 is in position mounted on the body structureelement 30, the fixing element 48 is entirely engaged inside the block46.

The bottom part 98 of the fixing element 48 has dimensions greater thanthe hole 92. Because of this, when it is progressively introduced intothe block 46 under the screwing force, it causes a radial deformation ofthe block 46 and, because of the elasticity of the material of the block46, a radial bulge 102 on the block 46 forms.

This radial bulge 102 has an outside diameter “D1” greater than theoutside diameter “D” of the block 46 and therefore the diameter of thehousing 68, which makes it possible to use the radial bulge 102 for theaxial connection of the base plate 32 to the block 46.

The dimensions of the radial bulge 102, which depend on the inside “d”and outside “D” diameters of the block, and the dimensions of the bottompart 98 of the fixing element 48, as well as the material constitutingthe block 46, are determined so that the base plate 32 can bedisconnected from the block 46 at the time of impact. Thus, at the timeof impact, the base plate is pushed downwards and, because of theelasticity of the block 46, the force of the base plate 32 on the radialbulge 102 causes a deformation of the radial bulge 102 allowing axialsliding of the base plate 32 with respect to the block 46 and thusseparation of the base plate 32 from the body structure element 30.

The elasticity of the block 46 can vary according to climaticconditions, in particular according to the outside temperature. Thus itmay happen that, for certain conditions, the deformation of the bulge102 requires that the magnitude of the impact be greater. This isunacceptable in the case of pedestrian impact.

To avoid this, the fixing element can comprise a rupture initiation areawhich is determined so as to rupture during an impact whose magnitude isgreater than the magnitude of an impact for which the bulge 102 deformsunder normal climatic conditions.

It will be understood that simple mechanical reversals may constitutevariant embodiments of the invention. For example, the block 46 can befixed to the base plate 32 by the fixing screw 54, and the bodystructure element 30 can be received in the groove 69 in the block 46.

The invention therefore allows the fixing of a wiping device 20 on abody structure element 30 which allows separation of these elements atthe time of an impact. In addition this fixing is composed of a largenumber of standard elements, which makes it possible to reduce themanufacturing cost thereof.

1. An arrangement for fixing a wiping device for a motor vehicle, of thetype comprising at least one stand for guiding in rotation and fixing adrive shaft which extends axially in a substantially vertical direction,of the type in which the stand comprises a barrel in which the shaft isguided in rotation, and a horizontal base plate for fixing the standwith a body structure element of the vehicle, by means of a damper blockmade from elastically deformable material, of the type in which thedamper block is fixed to the body structure element by a fixing elementcomprising a vertical rod which passes through the damper block andwhich is connected to the body structure element, and a locking elementfor the vertical locking of the damper block in the fixed position onthe body structure element, characterised in that the rod and lockingelement are connected by connection means enabling the rod and lockingelement to be disconnected, through a substantially vertical downwardsliding of the locking element with respect to the rod, when the wipingdevice is subjected to a violent impact whose vertical component isoriented downwards and is greater than a given value.
 2. The arrangementaccording to claim 1, characterised in that the connection meanscomprise at least one elastically deformable element.
 3. The arrangementaccording to claim 2, characterised in that the connection meanscomprise at least one element for retaining the locking element which isattached to the rod and which is able to disconnect from the rod at thetime of impact.
 4. The arrangement according to claim 2, characterisedin that the connection means comprise at least two lugs able to separateradially outwards received by the bottom end of the locking element, andwhose substantially vertical internal faces cooperate with the wall ofthe rod for the connection of the locking element with the rod.
 5. Thearrangement according to claim 1, characterised in that the connectionmeans comprise at least one plastically deformable element.
 6. Thearrangement according to the preceding claim, characterised in that therod comprises, close to its bottom end, at least one lug curved towardsthe outside which is in abutment against a bottom face of the lockingelement.
 7. The arrangement according to claim 5, characterised in thatthe locking element comprises a tubular and/or cylindrical sleeveextending substantially vertical which has the rod pass through it, theinternal wall of the tubular sleeve and the external wall of the rod(50) being connected by cooperation of complementary shapes (74 a, 74b).
 8. The arrangement according to claim 1, characterised in that theconnection means comprise at least one rupture initiation area.
 9. Thearrangement according to the preceding claim, characterised in that thelocking element (64) and the rod (50) are two parts of the same fixingelement (48), and in that the rod (50) is connected to the lockingelement (64) by the rupture initiation area (86).
 10. The arrangementaccording to claim 8, characterised in that the locking element isconnected to the rod by an intermediate element, and in that the lockingelement is connected to the intermediate element by the ruptureinitiation area.